Gun sights



H. C. SARVIS Sept. 17, 1957 GUN SIGHTS Filed April 15, 1953 2 Sheets-Sheet 2 5 m a N m C d m w m United States GUN SIGHTS Howard C. Sarvis, New Meadows, Idaho, assignor of one-half to Benjamin G. Gellenbeck, Tacoma, Wash.

Application April 13, 1953, Serial No. 348,296

7 Claims. (Cl. 33-58) This invention pertains to gun sights and relates particularly to the novel construction of a gun sight by which to obtain at once greater accuracy, speed and visibility than heretofore.

This application is a continuation-in-part of the abandoned application, Serial No. 74,983, filed February 7, 1949, and entitled Gun Sights.

There are three well-known forms of gun sights in common usage for firearms. One of these employs an upstanding blade or head at the muzzle end of the barrel and a V-notched sight at the breech end; the sighting eifort consisting of visually centering the bead in the notch, and placing the top central part of the head on the desired target sport. This type of sight can be aligned quickly and approximately enough for short-range shooting, but lacks accuracy at long range, because of the difficulty of spacing the bead in the notch while simultaneously trying to match the exact center of the head, by estimation, with a selected point on the target. The process is complicated by the fact that a substantial portion of the target is obscured by the sight elements.

The second form of conventional sight is known as the peep sight, utilizing a head or blade element at the muzzle end of the barrel and a circular aperture at the breech end in whichthe bead or blade is visually centered; the top center of the head or blade then being matched with a point on the target. This type is generally regarded as superior for long range shooting, though it retains the difficulty of matching the estimated center of a bead with a point on the target; also, for small or distant targets, the front bead obscures much or all of the lower part of the target. Because of the limiting effect of the small aperture, this sight is very slow to align at close objects or in bad light.

The third type of conventional gun sight is the telescopic sight which utilizes optical lenses for bringing the target into closer vision and employs crossed hairs or other fixed pattern as the sighting element. This type of sight is best employed for long range shooting, as the magnification is confusing at close ranges. It is expensive, easily rendered useless by moisture or dirt, and must be carefully handled to insure against damage and misalignment.

A fourth type of sight known in the art but of little commercial use comprises sight elements which comprise diametrically opposed quadrants of a circle. These quadrants are constructed either as solid opaque elements or as translucent or transparent colored quadrants. Aside from their questionable accuracy, the primary disadvantage of this type of sight resides in substantial masking and distorting coloring of the target area.

The four types of gun sights described above have certain common characteristics which represent disadvantages in their operation. For example, each of these types of sights vary in accuracy of use with different levels of illumination in the target area. Further, each is dependent for alignment, with but minor exceptions, upon the visual acuity of the eye. Under the best con- 2,806,288 Patented Sept. 17, 1957 2 ditions, with perfect eyesight, visual acuity is barely sufficient to exploit the possibilities of the modern gun; unfavorable conditions of individual eyesight, target contrast, glare, diffraction shift and many others may enlarge the errors of visual acuity far beyond those of the gun.

It is a principal object of the present invention to provide a gun sight constructed in such manner as to utilize Vernier acuity of the eye in aligning the sights, whereby to afford greater precision of sighting together with increased speed of aligning the sights at all ranges than provided by the sights described hereinbefore.

Another important object of this invention is to provide a gun sight wherein the front and rear sight elements are constructed to form sighting lines, whereby to afford use of Vernier acuity of the eye in aiming and simultaneously to afford maximum visibility of the target and the target area.

\ A further important object of this invention is the pro vision of a gun sight that is consistently reliable in use ilnder a substantial variation of illumination level of the target and target area.

A still further important object of the present invention is to provide a gun sight that affords viewing of ithe target and target area under actual conditions of illumination and color.

Still another object of this invention is the provision of a gun sight constructed in such manner that, when sighted, the sight elements appear at the target as superimposed crossed lines, with the eye focused naturally upon the target, so indicating a precise point on the target without necessity for estimation.

A still further important object of the present invention is to provide a gun sight which, although presenting thin sighting lines to the eye, is extremely rugged, will take severe treatment Without damage, and is readily adaptable to gun barrels of various manufacture.

A still further object of this invention is the provision of a gun sight which is of simplified construction and therefore of economical manufacture.

Another important object of the present invention is to provide a novel mount by means of which a gun sight element may be adjustably and detachably secured to a gun barrel, whereby to permit adjustment of the sight element to optimum distance with respect to the eye and to permit adjustment therein to compensate for periodic changes in the eyesight of the user.

The foregoing and other objects and advantages of the present invention will appear from the following detailed description taken in connection with the accompanying drawings, in which:

Figure 1 is a fragmentary side elevation of a gun barrel showing mounted thereon a rear sight element embodying the features of the present invention;

Figure 2 is a fragmentary side elevation of a gun barrel and showing mounted thereon a front sight embodying the features of the present invention;

Figure 3 is a fragmentary side elevation of a gun barrel and showing, in vertical section, detailed construction of the rear sight element shown in Figure 1;

Figure 4 is a sectional view taken along the line 4-4 in Figure 2 and showing the front sight element of Figure 2 as viewed from the position of the eye during aimings;

Figure 5 is a sectional view taken along the lines 5-5 of Figure 3 and showing details of construction of the rear sight element and mounting therefor;

Figure 6 is a sectional view taken along the lines 6-6 of Figure 3 showing the construction of the forward end of the support for the rear sight element;

Figure 7 is a fragmentary side elevation of a gun barrel showing mounted thereon a modified form of support for V the rear sight element;

Figure 8 is a sectional view taken along the line 8-8 in Figure 7; and

Figures 9, 10 and 11 are fragmentary elevations as viewed by the eye during aiming of the sights of the present invention and showing, respectively, the off-side misalignment of the sight element, the over-lapped misalignment of the sight element, and the co-linear, aligned arrangement of the sighting element.

Considered in its broad aspects, the gun sight of the present invention involves a construction of thin structural elements for the rear and front sights which, from the position of the eye when sighting, presents an open pattern of converging thin straight lines which are capable of being aligned in co-linear extension by the utilization of Vernier acuity.

The phenomenon of Vernier acuity involves the ability of a specific portion of the human eye to discern the relative displacement between two halves of a broken line. It has been determined that this ability of the eye is about 100 times as sensitive as perception by visual acuity. Thus, for example, the precision with which the eye can align two halves of a broken line is about 100 times the precision with which the eye can distinguish details by ordinary vision. For a complete discussion of the phenomenon of Vernier acuity, reference is made to Fundamentals of Optical Engineering by Donald H. Jacobs, 1943.

Although the phenomenon of Vernier acuity may be utilized effectively in aligning edges of side lines, it has been determined that the speed with which lines may be brought into coincidence varies according to the width of the lines. This is explained by the fact that both edges of a narrow line may be scanned simultaneously by the elements of the eye providing Vernier acuity, whereas only one edge at a time may be scanned when the line is wider than the angle of vision permitted by vernier acuity. This fact is of considerable advantage in the construction of the gun sight of the present invention, for it is well recognized by those skilled in the art of marksmanship and hunting that speed of aiming is an essential factor.

Referring particularly to Figures 2 and 4 of the drawings, therein is shown the preferred form of the front sight element 10 mounted upon the muzzle end 11 of a gun barrel. This front sight element comprises a base 12 which is cut away obliquely at its front and rear ends to form the beveled key section 13. This key section is adapted to be received and retained in the cooperating transverse key slot 14 formed in the upper side of the muzzle end of the gun barrel. The key section 13 may be secured within the key slot by any conventional means, it being preferred to construct these parts for a driving friction fit.

Secured to the base 12 along the side edges thereof are the flat metal plates 15, 16 which converge upwardly and are joined at their apex 17. The elements 12, 15 and 16 may be formed as a cast unit, if desired. Although the angle formed between the plates at the apex 17 may be varied within substantial limits, as desired, it is preferred that the angle be 90.

Referring now to Figures 1, 3 and of the drawings, there is shown a preferred form of rear sight element 20 adapted for mounting on the breech end 21 of the gun barrel. The rear sight comprises a base 22 to which is secured, or formed integral therewith, adjacent the lateral sides of this base, the spaced upstanding supports 23 and 24. The upper ends of these supports are curved inwardly toward each other, the said ends functioning to support the flat metal plates 25 and 26, respectively. These plates converge downwardly between the supports 23 and 24 and are joined together at the apex 27. The angle formed at the apex 27 is identical to the angle of the apex at the front sight 10, it being preferred, as previously mentioned, that this angle be 90.

The rear sight may be mounted upon the gun barrel in any manner desired, according to the well-known procedures. However, the rear sight element of the gun sight of the present invention is advantageously adapted to be adjusted relative to the frgnt sight 10 and the position of the eye in order tocompensat e'for optical deficiencies and eccentricities of the user. Accordingly, it is preferred that the rear sight element 20 be mounted upon the gun barrel in the manner and by means of the structural modifications illustrated in the drawings.

The gun sight mount shown in Figures 1, 3, 5 and 6 of the drawings comprises a structural base 30 having a top plate 31, side plates 32, 33 and a forward wall 34. The side plates are secured to the forward Wall and are tapered progressively rearward to reduce heighth, whereby the base is inclined upwardly toward its forward end to form a ramp. This,rarnp serves the dual purpose of providing adjustment of the sight for desired elevations and also effecting attachment of the mount to the gun barrel, as explained in detail hereinafter.

The side plates 32 and 33 are pressed inwardly along their length to form the inner guide grooves 35 and the outer beveled guide surfaces 36. Mounted slidably within the inner guide grooves 35 is a plate 37 having beveled edges corresponding to the angle of the guide grooves. This plate 37 is provided with a centrally positioned elongated slot 38 proportioned to receive therethrough the free ends of a securing band 39. The forward end of plate 37 is off-set downwardly to form a flange 40. Threaded holes are provided in this flange to receive the headed screws 41 which extend through non-threaded holes 42 in the forward wall 34.

Referring to Figure 6 of the drawing, it is to be observed that the lower edge of the forward wall 34 extends inwardly from the side plates 32, 33 a short distance to provide forward contact legs 43, and the intermediate edge portion of the wall 34 is curved arcuately upward. In this manner the inner edges of the legs 43 make contact with the gun barrel 21 and thus provides a space between the gun barrel and the lower edge of the side plates 32, 33. The rearward ends of the side plates engage the barrel, however, and thus the space provided between the gun barrel and the lower edges of the side plates diminishes progressively rearward from the front wall 34. The space formed in this manner at least half the length of the base is sufiicient to receive the securing band 39 therethrough for substantial adjustment along the length of the base.

In securing the base 30 upon the barrel, the free ends 44 of band 39 are reeved through the slot 38 in the plate 37 and then bent outwardly, as shown in Figure 5. The base is then slid over the plate 37, with the beveled edges of the latter engaging the inner guide grooves 35. These guide grooves extend substantially parallel to the top plate 31 of the base and thus they form a forwardly diverging angle with the surface of the gun barrel 21. Hence, as the base is forced rearwardly over the plate 37, the latter is drawn upwardly away from the gun barrel, thereby cinching the band 39 firmly about the gun barrel. This operation may be initiated by hand, with the final tightening being achieved by turning the screws 41 to draw the flange 40 and forward wall 34 more closely together.

The rear sight element 20 is adjustably secured to the base 30 as follows: Depending downwardly from the base 22 of the rear sight element is a flange 45, said flange being formed adjacent one lateral side of the base. The inner side of flange 45 is cut away obliquely to form a groove defined between the lower face of base 22 and the inner surface 46 of flange 45. This groove conforms with the angular construction of the outer surface 36.

The base 22 is bored transversely to slidably receive the screw 47. On one end of this screw there is secured a head 48 which carries a downwardly and inwardly projecting lug 49. This lug is tapered inwardly to conform with the angular construction of the outer guide surface 36. The side of base 22 adjacent the head 48 is preferably recessed to receive said head in order to present a smooth outer surface, said recess being deeper than the thickness of said head in order to permit drawing the lug 49 toward the flange 45 and thus grip the base 30 to secure the rear sight element 20firmly thereto. A knurled nut 50 is threaded onto screw 47 for this purpose.

The forward end of the beveled surface 36 is terminated short of the forward wall 34, as indicated at 51, to prevent accidental removal of the sight element ofi the forward end of the mount in the event the locking nut 50 should become loosened during carriage of the gun. Accidental removal of the sight element off the rearward end of the mount is prevented by the provision of the upstanding button 52 formed in the top plate 31.

A modified mount for the rear sight element 20 is illustrated in Figures 7 and 8. This amount comprises an elongated base 53 having downturned ends forming a rear leg 54 and a front leg 55. The front leg is longer than the rear leg, and thus the base is supported upon the barrel 21 in a position inclined upwardly toward the forward leg 55. The lateral edges of the inclined base are beveled inwardly, as at 56, for engagement by the inner surface 46 of flange 45 and the lug 49 of the rear sight member 20.

An elongated plate 57 having a central elongated aperture 58 therein is supported adjustably by the inclined base 53 on the under side of the latter by means of the spaced screws 59. These screws are received freely through openings in the base, with the screw heads 60 countersunk within the base below the upper surface of the latter. The screws are received in threaded holes formed in the elongated plate 57. Thus, as in the previous modification, the securing band 39 is wrapped around the gun barrel and its free ends 44 are reeved through the aperture 58 and bent outwardly between the adjacent surfaces of the plate 57 and the base 53. Then, by turning the screws 59 the plate is drawn upwardly toward the base and the band 39 is drawn securely about the gun barrel 21.

Referring now to Figures 9, l and 11, wherein the sight elements 15, 16 and 25, 26 are shown as they are presented to the viewers eye during aiming of the gun, it is to be observed that these lines formed by the edges of said elements appear to be of equal thickness. In order to provide this appearance, the actual thickness of the front elements 15, 16 is made thicker than the elements 25, 26 of the rear sight. The relative thicknesses of these elements will vary, of course, depending upon the distance separating said elements on the gun barrel and also depending in part upon the distance of the elements from the eye. For example, a very satisfactory gun sight construction for the conventional types of rifles is provided by constructing the front sight plates of steel having a thickness of 0.018 inch and the rear sight plates 25, 26 of steel having a thickness of 0.013 inch. The gun sight elements for a pistol are found to be very satisfactory with front sight plates having a thickness of 0.018 inch and rear sight plates having a thickness of 0.0l inch. These thicknesses may vary within limits and the rear sight element 2.0 may be adjusted to varying distances with respect to the front sight element within substantial limits without seriously afiecting the appearance of the lines of the sight as viewed from the aiming position.

With the gun sight elements properly mounted upon a gun, for example a rifle, the aiming operation is as fol lows: The rifle is held in proper position with the sighting eye looking down the barrel to the target. That is to say, there need be no conscious effort made to focus on the sight elements themselves, but rather upon the target and target area. In the event the front and rear sight elements are misaligned in a horizontal or vertical plane, as illustrated in Figures 9 and 10, the portion of the eye which functions with vernier acuity is instantly and positively activated by the said misaligment of lines. As the sighting is adjusted to bring the front and rear sight elements into co-linear extension to form the X illustrated in Figure 11, this aforementioned portion of the eye con-= tinually responds to tell the viewer when the sighting elements are precisely aligned, even though the eye is focused on the target far beyond the sighting elements themselves. The result of this aiming procedure is a precise alignment of the sighting elements to form a sharply defined X which appears in magnified form at the target. In this condition the aim of the gun may be altered, as in general practice, for example to follow a moving target.

Since the eye is focused upon the target and target area. in the normal process of seeing and the sight elements appear superimposed upon the target with no conscious effort being required in sighting the elements of the gun sight, the usual sighting errors due to such disturbing factors as excitement, tenseness and physical exertion are minimized. This is achieved by virtue of the fact that the sight elements appear in magnified form superimposed upon the target and therefore required corrections in alignment of the sight elements are more readily apparent under vernier acuity than are corrections required in conventional sights which utilize visual acuity for alignment. Further, since no actual scanning of the sight elements is required for sighting, the speed by which the sight elements are brought into alignment is greatly increased. This is of utmost importance, for example, when sighting upon a moving target, such as wild game.

A further important advantage of the gun sight construction of the present invention resides in the fact that the apex 17 of the front sight element 10 is overlapped by the apex 27 of the rear sight element 20. It is a general occurrence that the tip of the front sight element of a gun sight becomes worn and shiny from use and thus is capable of reflecting a considerable quantity of light. Varying degrees of error result from such reflection, depending upon the level of illumination and also upon the direction of illumination. This factor of error is completely eliminated in the gun sight construction of this invention.

From the foregoing it will be apparent that the present invention provides a gun sight which, for the first time, utilizes that portion of the human eye which provides for the greatest precision in sight measurements. Whereas under visual acuity the eye cannot detect misalignments of non-linear objects to greater precision than about half the thickness of the sight plates illustrated in Figures 9 to 11, the ability of the eye to detect extremely small misalignments of lines by vernier acuity renders the gun sight of the present invention superior both in accuracy and speed of aiming to the sights provided heretofore.

The gun sight of this invention is ideally suited for hunting game because the accuracy of sighting is not adversely affected by substantial changes in illumination level and the target and target area are seen in full view and in natural color. Furthermore, no conscious effort is required in sighting the sight elements, it being necessary only to look through the sight elements and focus naturally upon the target and target area.

By operation of vernier acuity the edges of the sight elements form crossed lines which appear in sharp detail as a large X superimposed upon the target area and the target. It is for this reason that the sights of the present invention are ideally suited for the training of a novice and are of particular merit in improving and maintaining With consistency the marksmanship of experts. It is generally recognized among experts in the art of shooting that the sights of conventional construction are, under many circumstances, less arcuate than the gun itself, and this is substantiated by comparative tests with conventional sights and with the sights of the present invention by the substantially greater precision and the consistency of precision achieved with the latter.

It will be apparent to those skilled in the art that various changes may be made in the details of construction illustrated and described hereinbefore without departing from the scope and spirit of the present invention. Accordingly, it is to be understood that the foregoing description is merely illustrative of the invention and is not to be considered in a limiting sense.

Having now described my invention and the manner in which the same may be used, what I claim as new and desire to secure by Letters Patent is:

l. A sight for guns and like aiming devices, comprising front and rear sight members, one of said sight members being formed of two only converging leg elements which intersect at an apex, the other sight member being formed of two only complementary converging leg elements which intersect at an apex, the converging leg elements of the front and rear sight members including identical angles, each of the leg elements being of uniform thickness when sighting whereby to form parallel inner and outer edges, the front and rear sight members being proportioned in such manner that when properly sighted the apexes of the front and rear sight members overlap and the outer edges of the two leg elements of one sight member are aligned in linear extension with the inner edges of the two complementary leg elements of the other sight member with the point of intersection identifying the point sighted upon.

2. The sight of claim 1 wherein the leg elements of the front sight member comprise thin structural elements forming an open pattern of an inverted V and adapted to be viewed edgewise, and the leg elements of the rear sight member comprise thin structural elements forming an open pattern of a V and adapted to be viewed edgewise.

3. A sight for guns and like aiming devices, comprising front and rear sight members, one of said sight members being formed of two only converging leg elements which intersect at an apex, the other sight member being formed of two only complementary converging leg elements which intersect at an apex, the converging leg elements of the front and rear sight members including identical angles, each of the leg elements being of uniform thickness when sighting whereby to form parallel inner and outer edges, the front and rear sight members being adapted for mounting on an aiming device in such manner that when the device is properly aimed the apexes of the front and rear sight members overlap and the outer edges of the two leg elements of one sight member are aligned in linear extension with the inner edges of the two complementary leg elements of the other sight member with the point of intersection identifying the point on which the device is aimed.

4. A sight for guns and like aiming devices comprising front and rear sight members, one of said sight members being formed of two only converging leg elements which intersect at an apex, the other sight member being formed of two only complementary converging leg elements which intersect at an apex, the converging leg elements of the front and rear sight members including identical angles, each of the leg elements being of uniform thickness when sighting whereby to form parallel inner and outer edges, and mounting means for securing the front and rear sight members on an aiming device in such manner that when the device is properly aimed the apexes of the front and rear sight members overlap and the outer edges of the two leg elements of one sight member are aligned in linear extension with the inner edges of the two complementary leg elements of the other sight member with the point of intersection identifying the point on which the device is aimed.

5. The sight of claim 4 wherein the leg elements of the front sight member comprise thin structural elements forming an open pattern of an inverted V and adapted to be viewed edgewise, and the leg elements of the rear sight member comprise thin structural elements forming an open pattern of a V and adapted to be viewed edgewise.

6. The sight of claim 4 wherein the mounting means for the rear sight member comprises an inclined elongated base member adapted to adjustably support the sight member thereon and adapted to be supported upon an aiming device in spaced relation therewith, a plate member supported by the base member on the under side thereof, elongated grooves in the sides of the base member extending obliquely with respect to the adjacent surface of the aiming device, the grooves receiving the sides of the plate member therein for sliding movement along the length of the base member, a flexible band adapted to encircle the aiming device, and means securing the band to the plate member, whereby to secure the band firmly about the aiming device by drawing the plate member away from the aiming device and thereby firmly securing the base member to the aiming device.

7. A mount for a sighting element for guns and like aiming devices, comprising an inclined elongated base member adapted to adjustably support a sighting element thereon and adapted to be supported upon an aiming device in spaced relation therewith, a plate member supported by the base member on the under side thereof, elongated grooves in the sides of the base member extending obliquely with respect to the adjacent surface of the aiming device, the grooves receiving the sides of the plate member therein for sliding movement along the length of the base member, a flexible band adapted to encircle the aiming device, and means securing the band to the plate member, whereby to secure the band firmly about the aiming device by drawing the plate member away from the aiming device and thereby firmly securing the base member to the aiming device.

References Cited in the file of this patent UNITED STATES PATENTS 526,588 Strandwold Sept. 25, 1894 647,123 Warner Apr. 10, 1900 766,447 Kiessig Aug. 2, 1904 1,048,876 Raedel Dec. 31, 1912 1,428,389 Miller Sept. 5, 1922 1,715,203 Loomis May 28, 1929 1,939,191 Vibber Dec. 12, 1933 2,093,676 Hennessy Sept. 21, 1937 2,256,411 Russell Sept. 16, 1941 2,353,133 Gorman July 11, 1944 2,553,540 Beckerman May 22, 1951 FOREIGN PATENTS 193,658 Switzerland Jan. 3, 1938 OTHER REFERENCES Pages 86 and 87 of Fundamentals of Optical Engineermg by Donald H. Jacobs, first edition, McGraw-Hill Book Co., New York, N. Y. Copyright 1943. 

